Digital video capabilities can be incorporated into a wide range of devices, including digital televisions, digital direct broadcast systems, wireless broadcast systems, personal digital assistants (PDAs), laptop or desktop computers, tablet computers, e-book readers, digital cameras, digital recording devices, digital media players, video gaming devices, video game consoles, cellular or satellite radio telephones, so-called “smart phones,” video teleconferencing devices, video streaming devices, and the like. Digital video devices implement video compression techniques, such as those described in the standards defined by MPEG-2, MPEG-4, ITU-T H.263, ITU-T H.264/MPEG-4, Part 10, Advanced Video Coding (AVC), the High Efficiency Video Coding (HEVC) standard presently under development, and extensions of such standards. The video devices may transmit, receive, encode, decode, and/or store digital video information more efficiently by implementing such video compression techniques.
Video coding standards (e.g., HEVC/H.265, H.264, H.263) utilize block-based processing at the video encoder, wherein prediction blocks (i.e., from inter or intra prediction paths) are subtracted from original pixels, and wherein residuals are transformed into coefficients using a forward transform (e.g., discrete cosine transform (DCT)), quantized, and entropy-coded (e.g., via CAVLC or CABAC). At the video decoder, the coefficients are entropy-decoded, de-quantized, inverse transformed, and then added back to prediction blocks to form reconstructed pixels.
In HEVC, the video encoder includes high complexity modules for mode decision and motion estimation, due in part to the video encoder checking all different coding unit (CU) sizes (i.e., 64×64, 32×32, 16×16, and 8×8) to identify the optimal coding modes and the CU/prediction unit (PU)/transform unit (TU) structures of each coding tree unit (CTU), which adds substantially to the complexity of the HEVC encoder. In this context, there remains a need for a technique to reduce the complexity of the encoding/decoding process.